The concept image of the iPhone 5S shows a larger screen in a funky, bright turquoise colour. The phone does resemble the iPod touch and confirms with rumours suggesting coloured variants of the next iPhone.

The second image shows the concept images in variants, the red one is smaller while the turquoise image is larger. Both are compared to the present day iPhone.

Could these mean that the rumours suggesting there will be cheaper, smaller variants of the next gen iPhone are true?

The iPhones seem to be made of plastic or some cheaper component making way for further suggestions of a cheaper, smaller iPhone.

Apple has retained the overall block-like design and there aren't any major changes. The colors have created a visible difference to the iPhone and it now looks brighter and more alluring!

Does this mean that Apple will be releasing the iPhone 5S (said to be the mini version) and iPhone 6, both in a go this year?

The concept images are from Martin Hajek. Martin Hajek is well-renowned for designing futuristic Apple devices and Apple has often confirmed to the designs conceptualised by him.